Talking with your hands is innate, study finds

Good news for those of you who are so self-conscious about gesturing when speaking you issue that “I use my hands when I talk” line: You can stop apologizing.

As Spencer Kelly, the co-director of Colgate University’s Center for Language and the Brain will tell The Acoustics 2012 Hong Kong scientific conference later today, gesturing is integral to language. In fact, he argues, it’s “innate.”

“Blind people gesture, even if they are blind from birth,” he explained in an interview. “They often gesture even when talking to other blind people. So there is some kind of predisposition to using our hands.”

A recent experiment he conducted shows that gesturing as speech is different from actions upon real objects. It’s more like language.

He placed EEG devices on the heads of subjects to monitor the electricity inside their brains as they viewed videos of people speaking. In some, people used gestures. In others, people took a real action on a real object. For example, in one scene, people pantomimed stirring a cup of coffee, in another, they stirred an actual cup of coffee. Scenes also depicted both gestures, and real use of an object, that were incongruent with the words so that, say, “He found the answer” was accompanied by a gesture indicating stirring something in a cup.

As the subjects viewed the videos, Kelly and colleagues looked for a specific electrical signal that indicates how strongly the brain is integrating one piece of information with another.

The results indicated that test subjects had more difficulty integrating words and real actions, than they did words and gestures. They also had more trouble integrating words with incongruent gestures than they did real actions.

So real actions tended to interfere with understanding speech, while gestures helped, but incongruent gestures interfered with understanding words while there was no difference between the amount of difficulty real actions posed whether they were incongruent or not.

That means, Kelly believes, that the brain views gestures as speech, but actions on objects as unrelated to speech. “That is kind of a controversial theory,” he said, “but my work and that of colleagues interested in testing it shows that gesture is more part of language than actions on objects.”

Gesturing, he thinks, has evolved. “I think it started with concrete interactions with objects,” he explained. “If I wanted to show you how to build a fire, I would bang two rocks together.” Over time, the real action was replaced by symbolic gestures and words. “Language is the ultimate abstraction,” he said. “Gesturing is a sort of middle ground between doing something and talking about something.”

Other experiments have shown that gestures are interpreted by the auditory cortex of the brain, like speech. And, interestingly, people with Broca’s aphasia, which can be caused by a stroke that damages the frontal gyrus, which pays a role in speech production, also have trouble gesturing.

So gesturing really does appear to be important for making ourselves understood. “The cool thing is,” Kelly said, “that if you’ve not thought about it, and then you start, you see it all the time. In fact, I’m talking to you right now on the phone and I’m gesturing.”